Thermostat.



f UNITED sTATEs PATENT oEEioE.

JULIUS BOEKEL, 0F PHILADELPHIA, PENNSYLVANIA.

THERMOSTAT.

Specification of Letters Patent.

Patented Feb.l '7, `1911.

Application filed April 30, 1910. Serial No. 558,706.

To all 'whom itimay concern:

Be itknown that I, JULiUs BOEKEL, a citizen of the United States,residing at'Philadelphia,

in the county of Philadelphia and State of' Pennsylvania,

have invented certain new and useful Improvements in rIhermostats; and Ido hereby declare the follow-,

ing to bel a full, clear, and exact description of the invention, suchas will enable others skilled in the 'art to which it appertains to makeand use the same. f

This invention relates to thermostats and moie particularly to the meansof adjusting the same. f

It also relates to the particular construcv tion of the adjusting screwand other fea tures hereinafter set forth. Its object is to .provide aliner and larger range of'adjustment, to provide an escape for the airwhich would otherwise be compressed at the top of the mercury chamberand so hamper the eX- panding of the latter and to produce a cheap,simpleand perfect instrument, all of these objects being attained by theconstruction and vcombination of parts hereinafter more particularly setforth and claimed.

' In the accompanying drawings: Figure 1 represents a view in viceembodying my invention, circuit wires.

a and Z)y being connected to their respective 4 posts land being brokenod short, and a battery through which one of said wires runs. Fig. 2represents a verticalA sectional view through the thermostat, .inittingthe wires and battery;v ig. 3 represents an enlarged detail view of theadjusting screwas shown inv Fig. 2; and Fig. 4 represents a slightmodification in the upper part of my inven tion, in which the air-ventextends through from the side ofthe plug.

1 designates a .long cylindrical tube for holding the mercury. Said tubeis provided Awith external screw threads on itsuppei end and a slotacross its bottom end for assisting in screwing and unscrewing the tubeor receptacle. maybe of any metal or other substance ,that will act asasuitable conductor for'the"`elec' tric 'current or ,thev contacts mightbejrunv through a non-conductor material' -tofthel mercury.

12 designates fitsjtightly the .attaching collar,` which around thetube1 just below the screw-threads'before mentioned, for the wire llandiis'p-r'ovided with a laterally projecting. lstud B.

Thisstud ris provided withfa hole' frontelevation of a de vis screwedinto A electric contactl The material iised inv said tube; certainpredetermined degree ofv heat has for the insertion of said wire a andis screw-l tapped in its end to permit the thumb-screw 5 to be screwedinto the stud and to project into the hole 4. After the wire a isinserted in the hole t the screw 5 will be screwed into the stud andwill engage and bind the wire a firmly in position.

6 designates a block, closure or plug composed of some non-conductibleor insulating material having an internally' screwfthreaded recess 7 inits lower end corresponding in size to the external size of theexternally screw-threaded end of tube 1. Saidv I:plug has a straighthole or channel 8 extending straight through from its ,top to thetop cfsaid recess and an internally screw-threaded.

recess 9, which extends only part way from the top Cif/'said plug. A.slantingchannelvor passage y10 connectsvthe lower part of. this v 9 withthe top ofgthe Irecess 7 at a point near the lower end ofi channel 8.Said plug is screwtapped :at'a

screw-threaded recess point near its" .top to allow the insertion-of thescrew 11 at right angles to and entering into the channel 8. I

12 designates the plunger rod which passes through channelS and islocked in any desired petition by means of the screw `11. `ner desired,in the present instancebeing merely provided .ular intervals,

This rod may be graduated in' any man# with circular inarks at reg; Ithas for its object to enter the mercury and, being ofmedium size, to

cause the rise .of the mercury in the tube when the rod. is lowered`and-'to cause the lowering ofv the mercury when the rod is partiallywithdrawn from the tube. it will be seen that by causing the rise andfall of the mercury this rod itself aids. greatly in the adjustment ofthe thermostat, giving it a very wide range or adj ustinent.

13 designates thevadjusting screw' which the internally screw-threadedrecess 9 and the pointl 15 of 'which makes with the mercuryA when aThus,

been attained, thus forming the circuit. l

The thermostatic device-has therefore a liquid .contactA and j a solidcontact whichy close thelelectricl circuit when they meet.

Each of .these isv independent-ly adjustable towardthe otheiginorder'thatthe making j Furthermore the screw. 13 takes part inboth ofthese adjustmentsfor it iio supplies the air-vent which makes the actionof pluno'er 12 on the fluid possible, besides positively adjusting` thecontact point 15 toward or from said duid. The wire Z) beforementioned'is secured to the upper' end of this screw and around thegroove near the lower end of the head of the'sci'ew. It might be securedto this screw of course in any suitable manner. vSo far this screw isold, but it embodies a feature which is thought' to be new. This is thevertical groove 14, extending only as far up and down as thescrew-threads, thus allowing communication between the inside of thetube and the atmosphere when the screw is not turned home and preventingthe escape of or loss4 of mercury when the screw is turned home forconvenience in shipping the article' from point to point or carrying it.

This thermostat may of course be used for regulating a heater system,for giving an alarm or other purposes of a somewhat similar nature andtherefore I have thought it best to show the thermostat by itself, withitsbattery and the two wires of the circuit, but no particular device tobe operated, for it makes no dilference what it operates. l

The mercury in the tube extends to nea-r the top thereof (see Fig. 2).

In the modification shown in Fig. 4 the air vent 16, extending throughthe side of plug 5 from the' lower end of the screwthreaded recess 9takes the place of, the groove 14 and is closed in the same way,

that is,'by turning the screw tightly home.v

The operation is as follows: Say the device is adjusted to work or toclose the circuit at SOdegrees in the drawings. lVhen that temperatureis reached the contact of point 15- and the mercury will take placeclosing the circuit and operating the apparatus which iteontrols. If itbe desired to adjust the thermostat to close the circuit at 70' degrees,the screw 11 is given about half a turn and the plunger is lowered one`mark when the screw is again tightened to lock the plunger rod inplace. This forces the'rod farther' down into the .mercury in the tubeand necessarily causes a Vhigher level of the saine. Ot' course itwillnot have to expand so much to form a contact with the point 15. If onthe other hand it be desired to adjust the thermostat to form a circuitat 90 degrees the screw 11 is given a half turn and the plunger isywithdrawn one mark when the screw is again tightened to lock theplunger rod in place. This action of course withdraws the rod one markfrom the former position in the mercury and necessarily causes a lowerlevel of the same, thus it will have to expand more to make the contact.

The screw 13has of course a fair range of they both might be adjusted totheir widest range, but it is quicker to adjust roughly by one andthen'to adjust finely by the other and as said before it gives a verywide range of adj'ustability.

Having thus 'described my invention, what I claim as new and desire tosecure by Letters Patent is:

In a tliermostatic device forming part of an electric circuit, areceptacle for containing conducting fluid, in combination with aplunger for mechanically raising or lowering the level of said Huid atwill, a closure for said receptacle having a bore through which saidplunger moves, also a threaded passage in the closure leading to theinterior of said receptacle and a screw engaging the threads of saidpassage for adjustment and having at its lower end a contact point whichenters said )assage and may be adjusted up or down tierein, this` screwbeing also provided with an air-ventI groove substantially as set forth.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses.

l v JULIUS BOEKEL. Witnesses JOHN H. Scimmia, F. MANGOLD.

